Understanding Detail Forecasts
Detail forecasts are based on individual items. Use detail forecasts to project demand at the single item level, according to each item's individual history.
Forecasts are based on sales data from the Sales Order History File table (F42119) and the Sales Order Detail File table (F4211). Before you generate forecasts, you use the Refresh Actuals program (R3465) to copy sales order history information from tables F42119 and the F4211 into the Forecast File table (F3460). This table also stores the generated forecasts.
You can generate detail forecasts or summaries of detail forecasts, based on data in table F3460. Data from the forecasts can then be revised.
After you set up the actual sales history on which you plan to base the forecast, you can run the Forecast Generation program (R34650), to generate the detail forecast for one or multiple items. You can then revise the forecast to account for any market trends or strategies that might make future demand deviate significantly from the actual sales history.
The system creates detail forecasts by applying multiple forecasting methods to past sales histories and generating a forecast that is based on the method which provides the most accurate prediction of future demand. The system can also calculate a forecast that is based on a method that you select.
When you generate a forecast for any method, including best fit, the system rounds off the forecast amounts and quantities to the nearest whole number.
When you create detail forecasts, the system:
Extracts sales order history information from the Forecast File table (F3460).
Calculates the forecasts by using methods that you select.
Calculates the percent of accuracy (POA) or the mean absolute deviation (MAD) for each selected forecast method.
Creates a simulated forecast for the months that you indicate in the processing option.
Recommends the best fit forecast method.
Creates the detail forecast in either dollars or units from the best fit forecast.
The system designates the extracted actual records as type AA and the best fit model as BF. These forecast type codes are not hard coded, so you can specify the codes. The system stores both types of records in table F3460.
When creating detail forecasts, the system enables you to:
Specify the number of months of actual data to use to create the best fit.
Forecast for individual large customers for all methods.
Run the forecast in proof or final mode.
Forecast up to five years into the future.
Create zero forecasts, negative forecasts, or both.
Run the forecast simulation interactively.